Vibration-reducing mounting device for signaling systems



June 10 192%. 3,46,7fi8

w."r. BOOTH ET AL VIBRATION REDUCING MOUNTING DEVICE FOR SIGNALINGSYSTEMS- Filed March 27. 1918' 2 ShQaQa-Sheet 1 co 2 N JOL- /nven70rs:wk VVf/l/am TBooih L1: Wa/ A, Boyd June 10 1924. 1,496,768

W. T. BOOTH ET AI...

VIBRATION REDUCXNG MOUNTING DEVICE FOR SIGNALING SYSTEMS Filed March 27.1918- 2 Sheets-Sheet. 2

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WET-JAM T. BOOTH, OF EAST ORANGE, NEW JERSEY, AND WALTER A. 3021), OF

BROOKLYN, new YORK,

ASSIGNORS TO WESTERN ELECTRIC COMPANY, INCOR- POBATEID, OF NE'W.YOR;K,N. Y., A CORPORATION OF NEW YORK.

' RATION-REDUCING MOUNTING DEVICE FOR SIGNALING SYSTEMS.

Application filed March 27, 19181 Serial N0. 225,124.

To all whom it may concern:

Be it known that we, WILLIAM T. Boorrr and WALTER A. BOYD, citizens ofthe United States, residing at East Orange, in the county of Essex andState of New Jersey,

and at Brooklyn, in the county of Kings and State of NewYork,.respectively, have invented certain new and useful Improvements inVibration-Reducing Mounting De- 1 vices for Signaling Systems, of whichthe following is a full, clear, concise, and exact description. 7

This invention relates to means for mountin electric discharge devicessuch as vacuum tu es or equivalent elements, particularly for mountingvacuum tubes upon vehicles or in other places where they are subject toshocks, jars or vibrations.

It has been found that the electrodes of W vacuum tubes as they areusually constructed almost always tend to act as vibratory systems withsmall damping factors. In a single vacuum tube there are in someinstances two control electrodes or grid elements, two cathode elementsand an anode consisting of two or more filament sections.

Since any relative movement of the electrodes or parts thereof variesthe output or s ace current which-passes in a circuit in- 9 c uding' thecathode and anode of such a tube, it is seen that shocks or vibrationsimpressed upon the tube so as to cause the several electrodes to vibratein their several respective periods will cause troublesome noises in atelephone bridged across the output circuit of the tube. Especially isthis true when several amplifier tubes are connected in tandem, wheneach tube in addition to am lifying the current variations of the preceing tube will add a series of variations due to the vibrations of itsown elements. The trouble due to vibrations of the electrodes is notlimited to tubes in tandem, but is usually present where vacuum tubesare mounted on any solid structure subject to vibrations, such as anaeroplane or boat. The inventionis e ually applicable to tubes used asampli ers, detectors, generators, modulators, or for other pur- 60poses.

' The object of this invention-is to roduce a ractical structure toovercome t e difiicu ties mentioned. In the drawings, Figs.

1, 2 and 3 represent one formof device for accomplishing the desiredresults, and Fig. 4 one of the two similar ends of a slightly modifiedform. Fig. 1 is an elevation partly in cross section, Fig.2 is a planview, and Figs. 3 and 4 are perspectives.

Referring particularly to Figs. 1 to 3 inclusive, 1 represents asupport, such as the side of a cabinet within which radio apparatus oraudion repeaters are mounted. Brackets 2 are mounted upon support 1 andcarry the remaining apparatus. Plate 3 ismounted upon the brackets bymeans of bolts 4 which pass through, in the order named, the plate 3, alayer of sponge rubber 5, bracket 2, a second layer 6 of sponge rubber,and the metal plate 7. Bolt 4 does not touch 70 bracket 2. The plate 3is therefore resiliently mounted upon the brackets .2 by means of theporous or sponge rubber 5. The small battery 8, condenser 9 andtransformer 10 constitute elements of considerable mass and are rigidlyattached to plate 3. Any suitable elements of large mass may be used.The metallic plate 11 is supported u on the plate 3 by bolt 12 passingthrough ate 13, sponge rubber 14, plate 11, pieces 0? s onge rubber-15aid plate 3. Plate 11 an bolt 12 should not be in contact. Mounted u onplate 11 in any suitable manner are soc ets 16 of any sultableconstruction inwhich vacuum tubes 17 of the audion or threeelectrodetype maybe fixedly secured. The audions are of the usual type well knownin the art, as shown for example, in U. S. Patent No. 1,130,042, tovander Bijl and Nicolson, and, as is well understood, will 90 eachcontain one or more grids, filaments and anodes. The numeral 18indicates a ballast lamp and illustrates how any such devices which areless sensitive to shocks or vibrations may be conveniently mounted uponthe plate 3 where they will be protected against jars of a violentnature. Since plate 11 is of slight ma'ss and has elements of smallweight only mounted thereon, the rubber 14 and 15 is of light texture.Rubber pieces 5 and 6 are, on the other hand, of heavier texture.

In Fig. 4 is shown in perspective one end of a similar arrangement. Inthis case bolts 19 pass completely through plate 13, rubber 7 14, plate11, rubber 15, plate 3, My- 21,-

I rubber 5, 6, bracket 2 and plate 7. Parts held by bolts 19 as asupport for the heavy batteries which may be mounted in box 20. Flange21 may be rigidly attached to plate 3. One or more vacuum tubes or otherapparatus may be mounted upon plate 11.v

Neither bolts 19. i The structures shown are admirably adapted forsupporting audion tubes and produce a'maximum degree of quietness in theplate 11 nor bracket 2 should touch output of such tubes under difiicultoperat-' ing conditions, as in aeroplanes. The heavy sponge rubber 5, 6serves to absorb incoming shocks and vibrations. This action is aided bythe large mass of elements 8, 9 and 10 which absorb considerable energyin being set into motion, and at the same time give the plate 3 a lownatural period of vibration which may be lower. than that of any of thevacuum tube electrodes. The light sponge rubber 14, 15 is an additionalprotection to the tubes 17 and prevents movements of plate 3 from beingimparted to them. Furthermore, the sponge rubber seems to have a certainspecific dampin effect upon existing vibrations of the tu e electrodes.Other materials, particularly any spongy caoutchouc-like material orother material having resiliency and damping properties, are consideredthe equivalent of sponge rubber for this purose. However, sponge rubberhas been ound to be the most efiicient of substances tried. In additionto the properties of the rubber itself. the air cells contained thereinseem to act somewhat as a multitude 'of minute dashpots. While fivevacuum tubes are shown mounted together, any number of tubes which it isdesirable to associate together may be so mounted and may be as sociatedwith individual circuits or con-' element by another damping means upona I rigid support. It is also believed to be novel to associate two ormore such damping means of different characteristics and to associatetherewith an intermediate support bearing a suitable mass. No attempthas been made herein .to enumerate or describe all the possible dampingmaterials or means and other equivalent structures and devices which maybe used in carrying on the purposes of the invention, but the appendedclaims are intended to include such equivahuts except where otherwisespecified.

weaves What is-claimed is:

1. In combination, a support, an antivibration damping means attachedthereto, an intermediate support attached to said anti-vibration dampingmeans, a second anti-vibration damping means attached to saidintermediate support, and a vacuum tube secured upon said second dampingmeans, said supports and said tube being attached to said damping meansby means whereby their movement in all directions with respect to saiddamping means is limited solely by the restraint imposed by said dampingmeans.

2. In a combination according to claim 1, a comparatively large massrigidly connected to said intermediate support.

3. In combination, an element adapted to support one or more vacuumtubes, a support therefor consisting of resilient damping material, saidsupport being mounted upon a second element having a large mass rigidtherewith, and a support for said second element consisting of resilientdamping mate.- rial, said elements being connected to said supports bymeans preventing any movement in any direction relative to said supportsunless said movement causes compression or extension of said dampingmaterial.

4:. A mounting structure for a thermionic device including a socket forholding said device, a supporting body, and a plurality of interveninglayers of material having a high damping factor for mechanicalvibrations, said layers constituting the connection "between said socketand said supporting body, and said socket being incapable of movement inany direction relative to said body without distorting said layers.

5. Electrical apparatus comprising a comparatively rigid body, a secondcompare tively rigid body attached thereto by means of flexible dampingmaterial so that said bodies have limited movement with respect to eachother in all planes, a third rigid body attached to said second body byflexible damping material so that said second and third bodies havelimited movement with respect to each other in all planes and means forattaching a space discharge device to said third body.

6. In combination a vacuum tube having an anode, a cathode, and acontrol electrode in fixed relation to each other, a resilient supportfor said tube for preventing external vibrations from appreciablychanging the space relations of said electrodes, and another resilientsupport of denser material than the first support for preventingvibrations from reaching said first support.

.7. A vacuum tube device having an anode, a cathode, and a controlelectrode, a support for preventing external vibrations from changingthe space relations of said electrodes comprising sponge rubber, saiddevice being supported from a solid body in such a manner that asubstantial area of said sponge rubber is placed between two adjacentsurfaces of the supporting and supported bodies whereby the supportingand damping effect of a comparatively large volume of the sponge rubberis eifective in preventing vibrations from being transmitted to saiddevice.

8. A mounting arrangement for a space discharge tube having electrodesof Which the normal spaced condition is subject to displacement byexternal vibrations comprising a fixed element and an element bearingthe tube, said elements having spaced surfaces of substantial areaadjacent each other and a substantial volume of sponge rubber fixedlyheld between said surfaces by securing means which is free from contactwith one of said elements whereby a range of movement of said elementswith respect to each other is permitted subject only to the restraintimposed by said sponge rubber.

' In witness whereof, my name this 22nd day of March, A. D. 1918.

\VILLIAM T. BOOTH. In witness whereof, I hereunto subscribe my name this15th day of March, A. D., 1918.

- WALTER A. BOYD;

I hereunto subscribe

